This invention relates to a radio control transmitter exhibiting a training function for controlling a radio-controlled airplane, a radio-controlled helicopter or the like, and more particularly to a radio control transmitter which permits a pupil-side radio control transmitter and a teacher-side radio control transmitter to be interconnected through a trainer cable.
A radio-controlled object such as a radio-controlled airplane or a radio-controlled helicopter is generally controlled at a considerable distance between the radio-controlled object and a radio control transmitter. Also, the control requires skill and even a skilled operator often makes a control error. In particular, a beginner is likely to make an error in control to cause an expensive airplane or helicopter to crash, leading to breakage of the airplane or helicopter and therefore breakage of an engine and a receiver each mounted thereon.
In order to eliminate such a control error, two radio control transmitters interconnected as shown in FIG. 6 have been conventionally used for control training of an airplane or the like. A conventional radio control transmitter for the control training is constructed as shown in FIG. 7.
In FIGS. 6 and 7, reference numeral 101 designates a teacher-side radio control transmitter, 102 is a pupil-side radio control transmitter, 103 is a cable called a trainer cable for interconnecting both radio control transmitters 101 and 102 therethrough, 104 and 105 each are a trainer switch for carrying out changing-over between a teacher-side operator and a pupil-side operator, 106 and 107 each are a rod antenna for transmitting a radio wave therethrough, 108 and 109 each are a meter for monitoring, 110, 111, 112 and 113 each are a stick operated by the operator, 114 and 115 each are a power switch, 121 and 123 each are a high-frequency or radio-frequency circuit for outputting an encoded signal in the form of a radio wave, and 122 and 124 each are an encoder circuit encoding the amount of operation of each of the sticks or the like.
Control training by means of the radio control transmitters 101 and 102 interconnected as shown in FIG. 7 is carried out by turning on or closing a power switch of the teacher-side radio control transmitter 101 to activate the radio control transmitter 101 and operating the sticks 110 and 112 to output a radio wave from the high-frequency circuit 121, resulting in taking-off of, for example, an airplane and lifting thereof to a safe altitude.
Then, the teacher-side operator changes over the trainer switch 104, so that the sticks 111 and 113 of the pupil-side radio control transmitter 102 may be operated, resulting in the airplane being placed in a controllable state. Thereafter, the pupil-side operator operates the sticks 111 and 113 to permit control training of the airplane to be carried out.
During control training by the pupil-side operators, only the teacher-side radio control transmitter 101 is kept activated, whereas in the pupil-side radio control transmitter 102, the amount of operation of each of the sticks 111 and 113 is encoded by the encoder circuit 124 and then transmitted in the form of a signal through the trainer cable 103 to the teacher-side radio control transmitter 101.
Then, changing-over of the trainer switch 104 permits an output of the encoder circuit 124 of the pupil-side radio control transmitter 102 to be applied to the high-frequency circuit 121 of the teacher-side radio control transmitter 101.
Thus, control of the airplane can be accomplished through operation of the sticks 211 and 213 of the pupil-side radio control transmitter 102 in place of operation of the sticks 110 and 112 of the teacher-side radio control transmitter 101.
When the airplane falls into an unstable state due to a control error during the control by the pupil-side operator or it is desired to land the airplanes the trainer switch 104 is returned to the original position to permit the teacher-side operator to operate the sticks 110 and 112.
The radio control transmitters 101 and 102 are not constructed for exclusive use for the teacher-side operator and pupil-side operator, respectively. Instead, radio control transmitters which are constructed so as to exhibit the same function are used for the radio control transmitters 101 and 102 and then connected to each other through the trainer cable 103, because such a general-purpose construction increases a value of a radio control transmitter.
Thus, of the radio control transmitters 101 and 102, the transmitter in which the power switch is first closed is determined to be the teacher-side radio control transmitter. Thus, when the power switch 114 is first closed, the radio control transmitter 101 is permitted to act as the teacher-side radio control transmitter, whereas when the power switch 115 is first closed, the radio control transmitter 102 is determined to be the teacher-side radio control transmitter.
In general, a pupil-side operator undergoing control training is typically a beginner, so that the pupil-side operator frequently makes misoperation of the transmitter because it is provided with a lot of switches. In particular, misoperation of an airplane by the pupil-side operator causes the pupil-side operator to be utterly confused, so that he often erroneously closes the power switch 115 of his own radio control transmitter.
Such misoperation causes a power to be fed to the high-frequency circuit 123 of the pupil-side radio control transmitter 102, resulting in the pupil-side radio control transmitter outputting a radio wave, so that a receiver mounted on the airplane experiences radio interference. This causes the airplane to be uncontrolled, leading to crashing or missing of the airplane.